Conventionally, a connector having a plug and a receptacle to be connected to the plug has been known. In this connector, the receptacle is packaged in an electric device or an electronic device, for example.
This connector may be provided with a lock mechanism for connecting the plug and the receptacle surely. Especially, a cable connecting connector is frequently provided with the lock mechanism.
This lock mechanism is demanded not only for connecting the plug surely to the receptacle but also, as the case may be, for disconnecting the plug easily from the receptacle.
For example, the following two are known as the connector provided with the aforementioned lock mechanism.
In the first connector, a pair of lock levers are disposed on the two widthwise sides of the cover of the plug, and an engagement portion is disposed in the receptacle for connecting the plug. Thus, the plug is connected to and disconnected from the receptacle while pushing the individual lock levers by bringing the hooks of the lock levers into engagement with the engagement portion of the receptacle (as referred to JP-A-6-29058, for example).
The second one is a micro-connector capable of pulling the plug forcibly out of the receptacle, as shown in FIG. 10. This micro-connector includes a plug 300 and a receptacle 400 into and out of which the plug 300 is inserted and extracted.
The plug 300 includes: a plug housing 301 having a flat plate shape; a shutter 305 having a rectangular cylinder shape for covering the rearward end side of the plug housing 301 and moving back and forth along the inserting direction of the plug 300; and a pair of compression coil springs 306 for urging the shutter 305 backward of the receptacle 400.
The plug housing 301 has an insulating property and has contacts 302 of a leaf spring shape arrayed in plurality in a dual-in-line shape. On the both side faces of the plug housing 301, lock springs 303, 304 which extend along the surface are disposed.
Rearward end sides of the lock springs 303, 304 are fixed on the side faces of the plug housing 301, but Forward end sides of them are free. The lock springs 303, 304 have arcuate hook portions 33A, 34B at their forward ends, and the arcuate portions of the hook portions 33A, 34B bulge outside.
Here, the plug housing 301 is connected on its rearward end side to the not-shown cable shielding clamp.
On the other hand, the receptacle 400 includes: an insulating receptacle housing 401 having a rectangular cylinder shape; a metallic shell 408 for covering the outer periphery of the receptacle housing 401; and contacts 403 of a flat plate shape disposed on the confronting upper and lower faces of the inner wall face of the receptacle housing 401.
The receptacle housing 401 is opened on its one end side to form an opening 402 into which the plug housing 301 of the plug 300 is inserted. Here, the upper face of the receptacle housing 401 is omitted from FIG. 10.
On those both side faces of the inner wall face of the receptacle housing 401 which have none of the contacts 403 disposed thereon, slide plates 404, 405 individually disposed. These slide plates 404, 405 respectively includes recesses 44A, 45B, which confront each other.
In the receptacle housing 401, a shutter plate 406 for moving back and forth in the axial directions, and a pair of compression coil springs 407 for urging the shutter plate 406 toward the opening 402 are disposed.
The shutter plate 406 is guided to move back and forth by the slide plates 404, 405 and the two contacts 403. The compression coil springs 407 are interposed between the other end side of the receptacle housing 401 and the shutter plate 406.
Moreover, the end portions of the slide plates 404, 405 on the side of the opening 402 are individually folded slightly inward. As a consequence, the shutter plate 406 can be prevented from jumping out of the opening 402.
The shell 408 of the metal plate has the not-shown tabs on its outer periphery. The not-shown tabs are welded to a printed-circuit board. As a consequence, the receptacle is fixed on the printed-circuit board.
Next, the actions of the micro-connector will be described in the following. The first description is made on the case, in which the plug 300 is to be connected to the receptacle 400.
First of all, the forward end of the plug housing 301 of the plug 300 is moved in the direction of an arrow G in FIG. 10 and is inserted into the opening 402 of the receptacle 400.
Then, the lock springs 303, 304 are pushed inward at their hook portions 33A, 34B by the slide plates 404, 405 so that they are elastically deformed in the directions to approach each other, that is, in the directions of arrows P of FIG. 10. At the same time, the rearward end of the plug housing 301 pushes and moves backward the shutter plate 406.
Moreover, the shutter 305 of the plug 300 is pushed by the wall face around the opening 402 of the receptacle 400 so that it moves back in the direction of an arrow R of FIG. 10 with respect to the plug housing 301.
When the forward end of the plug housing 301 of the plug 300 is further moved in the direction of an arrow G of FIG. 10, the hook portions 33A, 34B are fitted in the recesses 44A, 45B so that the plug 300 and the receptacle 400 are locked by the elastic restoring forces of the lock springs 303, 304.
Here, with the plug 300 and the receptacle 400 thus being locked, the shutter 305 and the shutter plate 406 are individually moved backward so that the contacts 302 and the contacts 403 are individually exposed and electrically connected with each other.
Next, here will be described the case, in which the plug 300 is to be removed from the receptacle 400.
In the state in which the plug 300 is connected to the receptacle 400, the plug 300 is pulled out of the receptacle 400 against the dragging resistance between the hook portions 33A, 34B of the lock springs 303, 304 and the recesses 44A, 45B. Then, the shutter 305 is urged to move in the direction of an arrow F of FIG. 10 by the pair of the compression coil springs 306. The shutter plate 406 is urged to move in the direction of an arrow H of FIG. 10 to shut the opening 402 by the pair of the compression coil springs 407.
In recent years, the electronic device such as a micro video camera or a mobile information terminal is rapidly small-sized. As a consequence, the connectors to be packaged in these electronic devices are desired to be small-sized. In this case, the contacts are disposed at a narrow distance. When the remaining parts slide on the contacts in the directions intersected by the plug inserting/extracting directions, they may deform the contacts to cause malfunctions.
In the aforementioned first connector, however, the plug is pulled out of the receptacle while pushing the lock levers of the plug with the fingers. As a matter of fact, the plug is pulled out of the receptacle while being shaken in the directions intersected by the extracting direction thereof. By these actions, the contacts may be deformed to cause failures between the contacts of the plug and the contacts of the receptacle.
In the aforementioned second connector, on the other hand, the plug is pulled out of the receptacle against the dragging resistance between the hook portions of the lock springs and the recesses. As a matter of fact, the plug is pulled out of the receptacle while being shaken in the directions intersected by extracting direction thereof. By these actions, the contacts may be deformed to cause failures between the contacts of the plug and the contacts of the receptacle.
In the second connector shown in FIG. 10, moreover, the plug 300 is locked in the receptacle 400 by the dragging resistance between the hook portions 33A, 34B of the lock springs 303, 304 and the recesses 44A, 45B. As a consequence, the locking of the plug 300 in the receptacle 400 is not reliable.
Therefore, the rigidity of the lock springs 303, 304 is enhanced to lock the plug 300 surely in the receptacle 400. Then, a high force is required for pulling the plug 300 out of the receptacle 400.
If the lock springs 303, 304 are made highly rigid, their hook portions 33A, 34B and the slide plates 404, 405 slide each other so that they are seriously worn. In addition, the end portions of the slide plates 404, 405 on the side of the opening 402 are also worn by the hook portions 33A, 34B, and the shutter plate 406 may jump out of the opening 402.
In a practical consideration, it is necessary that the plug 300 can be inserted into and extracted from the receptacle 400 by at least 8,000 to 10,000 times.